Liquid level control means



July 2, 1957 GRAHAM 2,798,135

LIQUID LEVEL CONTROL MEANS Filed Jan. 27, l95 6 2 Shets-Sheet 1 ZVENTOR.

Arrow/5Y5 F. O. GRAHAM July 2, 1957 LIQUID LEVEL CONTROL MEANS 2Sheets-Sheet 2 Filed Jan. 27,- 1956 INVENTOR. a m BY United Brae LIQUIDLEVEL CONTROL MEANS Application January 27, 1956, Serial No. 561,786

7 Claims. (Cl. 200-152) This invention relates to improved liquid levelcontrol means of apparatus for the simultaneous treatment of gaseous andliquid materials under superatmospheric pressures, of which liquidcarbonating apparatus is typical.

It is an object of the invention to provide for such apparatus liquidlevel electrode control means which is marked by great structuralsimplicity, compactness and ease of fabrication and which is reliable inoperation un der relatively high interior pressures and which by reasonof its compactness makes possible greater compactness and lower cost ofthe apparatus controlled.

With the foregoing objects in view the invention con sists in variousforms, arrangements and combinations of parts hereinafter described asembodied in the carbonating apparatus shown in the accompanyingdrawings, the

said invention being particularly defined by the claims appended to thedescription.

In the drawings,

Fig. 1 is a vertical sectional view of a carbonator embodying theinvention, the section being taken through the vertical axis of thecylindrical carbonator tank or shell, and the figure also including adiagrammatic show ing of automatic means for supplying to the tankliquid to be carbonated.

Fig. 2 is a plan view of the carbonator shown in Fig. l.

3 is a horizontal section on the line 3-3 of Fig. 1.

Fig. 4 is a detached axial sectional view of the electrode parts of theapparatus shown in Fig. 1, the view being on an enlarged scale and aportion of one of the electrodes being broken away to permit the largerscale illustration.

Fig. 5 is a horizontal section on the line 5-5 of Fig. 4.

Fig. 6 is an enlarged side elevation of the electric slip connector forone of the electrodes shown in Figs. 1 and 4.

Fig. 7 is an enlarged shown in Fig. 6.

Fig. 8 is a vertical transverse section of the electrical slip connectorof the ground conductor of the apparatus, the section being taken on theline 8-8 of Fig. 5.

Referring in detail to the construction illustrated in the drawings, 1designates as an entirety a carbonator em bodying the present invention.The carbonator comprises a blank or shell having a seamless tubular sidewall 2 of sheet metal, a bottom wall 3 also of sheet metal, and top wall4 of heavy metal plate, the joints between the side wall and the bottomand top walls, respectively, being suitably welded to provide ahermetically tight vessel.

Within the tank is a baflle structure generally designated by thenumeral 5, consisting of a tubular member 6 and a circular apertureddisc 7 welded to the lower end of the tube 6, the disc being formed witha central truncated cone part 701. The upper endor" tube 6 is welded tothe under side of closure plate 4 so that the baffie structure 5 isrigidly supported in the tank. The upper end of the tube 6 is notched at6a so that the space inside and outside of the tube are in freecommunication with each other at the upper end of the carbonatorchamber. The

plan view of the slip connector atent diameter of the circular bafiledisc 7 is somewhat smaller than the interior diameter of the shell wall2 so that there is a small circumferential opening a between theperiphery of disc 7 and the wall 2.

The closure plate 4 is formed with a threaded aperture to receive aliquid inlet fitting generally designated by the numeral 8 whichconsists of a tubular part 9 formed at its lower end with a nipplethreaded to engage the said aperture in the plate 4, a rubber checkvalve 10 of conventional type and a pipe coupling member 11 which isthreaded into member 9 and secures the check valve 10 in operativeposition. The lower end of the part 9 is formed with a straightelongated passage 9a designed to introduce liquid under pressure intothe carbonator in the form of a solid stream or jet pointed directlytoward the upper surface of the bafile disc 7, in a manner to avoiddirecting the introduced liquid through the opening a.

As shown in Fig. 2, the top plate 4 of the carbonator shell is providedwith a fitting 12 for the introduction of carbonic acid gas underpressure. This fitting 12 may be identical with the fitting 8 andadapted for connection to a cylinder of liquified carbon dioxide throughsuitable pressure control devices in a manner well known in thecarbonator art. Diametrically opposite the liquid inlet fitting 8 theclosure plate 4 of the carbonator shell is provided with an unthreadedaperture to receive a liquid outlet fitting 13, which is welded inposition in the plate with a hermetically tight joint. The upper end offitting 13 is threaded to receive a pipe coupling. A liquid dischargetube 14, which has its upper end welded in the bore of the fitting 13with a hermetically tight joint, extends downward to the bottom of thetank chamber where it is curved inward and has its lower open end 14adisposed approximately at the lower axis of the vertical shell and thecentral bafiie tube 6. The disc 7 is notched at 712 to accommodate tube14.

Within the baffle tube 6 and extending above the top wall 4 of thecarbonator tank is disposed improved liquid ameter to snugly fit theinner wall of the tubular elec trode 16 and support the rod electrode incoaxial relation to the tubular electrode.

The coaxial electrode unit thus formed is mounted in a support fitting19 by means of an insulating tube 20 which i preferably formed of solidplastic material such as Du Pont nylon. The inner surface of tube 20 hasa pressed fit on the electrode 16 and its outer surface has a pressedfit in the bore of the support fitting 19. The upper end of innerelectrode 17 extends above the insulating tube 18 and its lower endextends below the lower end of the insulating tube and is threaded toreceive an enlarged tip 17a of carbon or graphite in accordance withknown practice.

In the fabrication of the electrode unit comprising the electrodes l6,l7 and interposed insulating sheath 18, after the three elements havebeen telescoped together in the relation shown in Fig. 4, the outerelectrode 16 is compressed at a plurality of points along its length toform interior annular beads 16a which compress the plastic sheath 13 asshown in Fig. 4. This creates a corresponding number of zones extendinglongitudinally of the electrodes in which extremely tight fits areformedv between the outer electrode and the plastic sheath and betweenthe inner electrode and the plastic sheath. The. compressing or crimpingoperation on the outer electrode is preferably carried out by chuckingthe three-part electrode assembly in a rotary spindle and formingtheseveral internal beads of the outer electrode simultaneously by aspinning operation. By reason of the simultaneous compressing actions itwill be seen that the treatment positively compresses the plasticmaterial of sheath 18 occupying the spaces between adjacent beads aswell as establishing at the beads very high pressures between the twoelectrodes and the sheath. The result is that the jointsbetween therespective coaxial electrodes and the interposed sheath are renderedpermanently resistant to longitudinal leakage between the electrodes toan extremely high degree.

After the three-part electrode unit has been assembled in the sleeve thelatter is forced into the bore of the support 19. In this operation theouter surface of the sleeve 20, or the inner surface of the support 19,is advantageously coated with a suitable varnish such as GeneralElectric Glyptal No. 1294, which serves as a lubricant to facilitate theassembly and which, when hardened, additionally insures a liquid-proofjoint. It will be appreciated that in efiecting the force fit of theplastic sleeve 20 in the bore of the support 19 resultant inwardpressures are transmitted from the support to the joint between thesleeve 20 and the tubulareletcrode 16.

The lower end of the electrode support 19 is threaded to engage acentral threaded aperture in the tank plate 4 'so as to provide a tightjoint between the support and the said plate.

It will be noted, in Figs. 1 and 4, that the upper end of the electrodetube 16 extends somewhat above the insulating sleeve 20, thus providingan exposed cylindrical surface to receive the slip connector 21 of aconductor 22 (Figs.f6, 7). The connector 21 is in the form of a helicalwire coil of a diameter to slip over the end of electrode 16 byresiliently expanding slightly, the conductor being preferably formed atits upper end with a smaller diameter coil 21a to which the end ofconductor 22 is soldered.

Similarly the upper end of the inner electrode 17 which extends abovethe insulating sheath 18 is adapted to receive a slip connector 23 of aconductor 24 formed similarly to connector 21 but of suitable smallerdiameter to fit the smaller electrode.

To provide a ground connection for the electrical sys tern the conductorsupport 19 is formed with an upwardly extending collar having an innercylindrical surface 19a in which is slidably disposed a resilientexpansible connector 25 which is connected to a ground conductor 26. Theconnector 25 is in the form of an interrupted band (Figs. 5, 8), topermit its contraction and expansion, and is formed intermediate itsends with a loop 25a to receive the end of the conductor 26 andfacilitate the making of a soldered joint.

The collar of support 19 also is formed with a cylindrical outer surface19b to receive a tube 27 of a height to surround the lower ends of thecable 28 and its conductors 22, 24, 26. After the slip connectors of thethree conductors have been applied to the electrodes and the support 19as shown in Fig. 4, the space Within the tube 27 may be filled with asuitable sealing material 29 such as epoxy resin. Thus sealed, the upperpart of the entire electrode assembly and the electrical connectionsthereto are rendered completely water proof.

As is shown in Fig. 1, the cable conductors 22, 24 and 26 are extendedto a relay 30, which, in turn, is connected to the terminals of anelectric motor 31 which drives a rotary pump 32 connected to supplyWater or other liquid to the fitting 8 of the carbonator. The motordriven pump and the electrode control means operate in known manner toautomatically supply liquid to be carbonated and the electric devicesdiagrammatically indicated in the drawing may be of known charactersuch, for example, as those shown in U. S. Patent No. 2,249,994.

The top closure plate 4 of the tank 1 is preferably provided at a pointdiametrically opposite the gas inlet fitting" 12 with a threadedaperture to receive a relief J valve 32 (Fig. 2), such as is commonlyprovided for carbonator apparatus of the character in question.

In accordance with the usual practice all parts of the carbonatingapparatus which are contacted by the carbonating liquid are formed ofcorrosion-resistant metal, such as stainless steel.

With the carbonator connected to a source of CO2 gas adapted to supplythe gas at a suitable pressure, such as l00 p. s. i., and with theliquid pump connected with a source of liquid and designed to supplyliquid to the carbonator fitting 8 at a pressure of 120-140 p. s. i.,the operation of the apparatus is as follows.

The motor driven pump under control of the electrodes is started andstopped to maintain the level of the liquid in the carbonator betweenthe maximum and minimum levels coinciding with the lower ends of theelectrodes 16 and 17, respectively. When, because of draft of carbonatedliquid through discharge tube 14, the liquid level in the carbonatorfalls below the bottom of the electrode tip 17a and the pump 24 isthereby started, liquid at the pump discharge pressure is deliveredthrough'thc bore 9a of the supply-fitting 8 until the liquid level inthe carbonator rises to the bottom of the shorter electrode 16,whereupon the pump is automatically stopped. The liquid is deliveredthrough the bore of the fitting 8 in the form of a solid jet which isprojected into the body of liquid in the carbonator-at high velocity andcauses the liquid to vigorously boil and bubble in the presence of thecompressed gas which is maintained under the predetermined supplypressure. The space surrounding the bafile tube 6 and above the baffledisc 7 is thus occupied by a vigorously agitated mass of mixed liquidand gas and the large liquid surfaces thus developed favor rapidsolution of the gas in the liquid. However, the space within the baflietube 6 is relatively quiescent so that the electrodes are able toperform their motor control function with adequate uniformity. The spacebelow the bafiie disc 7, although it is in communication with the spaceabove the disc through the restricted circumferential opening a, is alsorelatively quiescent. Nevertheless, during withdrawal of carbonatedliquid from the carbonator, the space below disc 7 to a substantial.extent receives small bubbles of undissolved gas which pass downwardwith liquid through the opening a. As this mixture of liquid and bubblesmoves from opening a downward and radially inward toward the inletopening 14a of the discharge tube 14 the bubbles rise and find their wayinto baffle tube 6 where they move upward through the quiescent liquidand deliver their gaseous contents to the gas space above the liquidlevel in the carbonator. The use of the distinctively formed andarranged jet nozzle, bafile structure and carbonated liquid dischargetube herein disclosed is not herein claimed since it is the subject ofclaims in U. S. patent to Lance, No. 2,735,665.

It will be understood that in the operation of the carbonator it issubjected to an interior pressure at least equal to the carbonated gaspressure employed and that the joints of the carbonator structure mustbe hermetically tight. Since level-controlling electrodes supported inthe carbonator chamber must be insulated from the metal walls of thechamber the attainment of reliably tight joints between the electrodesand the carbonator'tank wall have always posed a somewhat difficultproblem. In the present carbonator this problem has been solved withnotable success by means of the construction which has been described.The relatively small diameter of the threaded section of the supportfitting 19 facilitates the attainment of a tight joint between thesupport and the top plate of the carbonator. Similarly the forced fit ofthe plastic sleeve 20 in the bore of the fitting 19 and on the tubularelectrode 16 insures permanently tight joints between these parts.Finally, the series of the annular beads 16a formed in the electrode 16with resultant high compression of the insulating sheath 18 between thetwo electrodes in a plurality of zones, produces joints between thesheath and the electrodes capable of withstanding extremely highpressures without leakage of gas.

As will be noted in Fig. 1 of the drawing, the small diameter of theelectrode assembly permits the use of a small bafiie tube 6. This, inturn, permits some reduction in the diameter of the tubular side wall 2of the carbonator tank without sacrificing the volumetric capacity ofthe agitation zone of the carbonator and the result is a reducedmaterials cost of the tank and bafiie structure.

The construction of the coaxial electrode assembly achieves additionalsavings in cost by virtue of reduction of the amounts of theconstruction materials employed, the utilization of standard rod andtubular forms for the metal electrode members and the ease with whichthe assembly of the electrode parts and the electrical connections iseffected.

It will be understood that the specific constructions of the improvedcarbonator which are herein disclosed and described are presented forpurposes of explanation and illustration and are not intended toindicate limits of the invention, the scope of the invention beingindicated by the following claims.

What is claimed is:

1. Electric liquid-level control means of apparatus for the simultaneoustreatment of gaseous and liquid materials under super-atmosphericpressure, the said means comprising the combination with a hermeticallyclosed metal tank for holding gas and liquid to be treated; of a metaltube-like electrode support having a gas-tight mounting in the top wallof the tank to provide a passage therethrough; a bushing of soliddielectric material disposed in the passage through the support with agas-tight forced fit therein; a tubular metal electrode extending upwardthrough and somewhat above the upper end of the bushing and having agas-tight forced fit in the bushing; and a rod-shaped electrode unit ofgreater length than the tubular electrode extending through the latterwith a gastight fit, the said unit comprising a metal rod and adeformable dielectric tube tightly fitting the rod with portions of therod exposed at each end of the dielectric tube and the said tubularelectrode being formed with a plurality of annular inwardly projectingbeads that highly compress the wall of the dielectric tube between thesurfaces of the beads and the surface of the electrode rod.

2. Control means as claimed in claim 1 in which adjacent annular beadsof the tubular electrode act also, in conjunction with the tubular androd electrodes, to maintain the material of the dielectric tube disposedbetween the adjacent beads in a state of positive compression.

3. Control means as claimed in claim 1 which additionally comprise threeelectrical conductors, two of which have end fittings having resilientslip engagement with the upper ends of the tubular and rod electrodes,respectively, and the third of which has resilient slip connection withthe upper end of the electrode support.

4. Control means as claimed in claim 3 in which the conductor fittingsfor slip engagement with the electrodes each consists of a primaryhelical wire coil formed to slip over and resiliently grip the upper endof its electrode and a secondary coil integrally attached to the primarycoil and soldered to its conductor.

5. Electric liquid level control means of apparatus for the simultaneoustreatment of gaseous and liquid materials under super-atmosphericpressure, the said means comprising the combination with a hermeticallyclosed metal tank for holding gas and liquid to be treated; of a metaltube-like electrode support having a gas-tight mounting in the top wallof the tank to provide a passage therethrough and being formed at itsupper end with an upstanding annular collar; a bushing of soliddielectric material disposed in the passage through the support with agas-tight forced fit therein; a tubular metal electrode extending upwardthrough and somewhat above the upper end of the bushing with a gas-tightfit therein; a rodshaped electrode unit of greater length than thetubular electrode extending through the latter, the said unit comprisinga metal rod and a deformable dielectric tube surrounding the rod withportions of the rod exposed at each end of the tube and forming agas-tight packing between the rod and tubular electrode elements; twoelectrical conductors having resilient slip engagement with the upperends of the tubular and rod electrodes, respectively; a third conductorhaving a resilient slip engagement with the inner surface of the annularcollar of the electrode support; an upstanding tube having its lower endtightly engaing the outer surface of the collar of the electrodesupport; and a solid body of dielectric material filling the upstandingtube and forming a water-proof cover for the lower end parts of thethree conductors.

6. Electric liquid level control means comprising a metal tube-likeelectrode support; a bushing of solid dielectric material disposed inthe passage through the support with a fluid-tight forced fit therein; atubular metal electrode extending upward through and somewhat above theupper end of the bushing with a fluid-tight fit therein; a rod-shapedelectrode unit of greater length than the tubular electrode extendingthrough the latter, the said unit comprising a metal rod and deformabledielectric tube surrounding the rod with portions ofthe rod exposed ateach end of the tube and the said tubular electrode being formed with aplurality of annular inwardly projecting beads that highly compress thewall of the dielectric tube between the surfaces of the beads and thesurface of the electrode rod; and three electrical conductors, two ofwhich have end fittings having resilient slip engagement with the upperends of the tubular and rod electrodes, respectively, and the third ofwhich has a resilient slip connection with the upper end of theelectrode support.

7. Electric liquid level control means comprising a metal tube-likeelectrode support formed at its upper end with an upstanding annularcollar; a bushing of solid dielectrical material disposed in the passagethrough the support with a fluid-tight fit therein; a tubular metalelectrode extending upward through and somewhat above the upper end ofthe bushing with a fluid-tight fit therein; a rod-shaped electrode unitof greater length than the tubular electrode extending through thelatter, the said unit comprising a metal rod and a deformable dielectrictube surrounding the rod with portions of the rod exposed at each end ofthe tube and forming a fluid-tight packing between the rod and tubularelectrode elements; two electrical conductors having resilient slipengagement with the upper ends of the tubular and rod electrodes,respectively; a third conductor having a resilient slip engagement withthe inner surface of the annular collar of the electrode support; anupstanding tube having its lower end tightly engaging the outer surfaceof the collar of the electrode support; and a solid body of dielectricmaterial filling the upstanding tube and forming a water proof cover forthe lower end parts of the three conductors.

References Cited in the file of this patent UNITED STATES PATENTS1,962,192 Hapgood June 12, 1934 2,414,607 Phillips Jan. 21, 19472,424,657 Goodman July 29, 1947 2,470,066 Calabrese May 10, 19492,514,463 Bayers July 11, 1950 2,623,969 Lyle Dec. 30, 1952 2,735,665Lance Feb. 21, 1956

